Safety timer governor



Patented June 19, 1928.

star EDWARD o, NEWTQN, or os AnsnLns, cn nrronnrn,

snrncrx TIMER eovEnnon.

Application filed May' 2, 1923. Serial no. 636,051.

My invention relates to a governor mechanism which is especiallyapplicable for use in automatically advancing or retarding the timingof'the ignition spark in internal combustion engine operations.

An object of my invention is to provide governor mechanism embodyinginstrumentalities adapted, on being rotated, to move under the action ofcentrifugal force,

10, said governor mechanism being so constructed and arranged that whenthe speed of rotation reaches a predetermined rate the centrifugal forcewill be diminished and resist ance to centrifugal force augmentedrelative 1 to increase in the speed of rotation, whereby a verysensitive action will be effected at both high and low speeds.

An object of my invention is to provide a governor mechanism with speedresponsive elements which operate under the action of centrifugal forceto produce anormal governing action at a normal speed of rotation, andto produce a graded governing action, at and beyond a predeterminedspeed, proportional with the speed. i

With the foregoing objects in View, to,- gether with such other objectsand advantages as may subsequently appear, my invention resides in theparts and in the combination, construction and arrangement of partshereinafter described and claimed;

The invention is illustrated in the accompanying drawings, in whichFigure 1 is a plan view of the rotary ele mentshowing the operatingparts thereon in normal position.

Figure 2 is a similar view with the operating parts in a partly advancedposition.

Figure 3 is a similarview with the operating parts in their maximumadvanced position.

Figure 4 is a view in cross section partly in elevation, showing thedevice as assembled. V

Fig. 5 is a perspective view of the supportmg element for thecentrifugally actuated parts. More specifically, 14 indicates a timershaft which is adapted-to be rotated in the usual manner from the crankshaft on an internal combustion engine.

In carrying out my invention I employ a centrifugal governor for openingand closing the ignition circuit at various moments relati e to theposit-ion of the engine pisten and to the engine speed, which governoris here shown as embodying a rotary element 24 fixed on the timershaft14. The rotary element-includes a sleeve 25 which is, rigidly secured tothe timer shaft in any desired manner, Formed onthe sleeve is a bracket26 on which is mounted a weighted arm 27 pivoted at 28 on'the bracket ata point eccentric to the axis of rotation of the rotary element, whicharm is adapted to be moved outwardly under the action of centrifugalforce.

A second bracket 29 is formed on the sleeve '25 and pivoted at 30thereonis a weighted lever 31, which isadapted to swing outwardly underthe action of centrifugal force o'nrotationof the rotary arm. Theweighted-lever 31 is designed to have limited outward movement, forwhich purpose it is formed with aj' shoulder 32 which is adapted to abutagainst the bracket 29 when the'lever is in its outermost position, asshown in Figures 2 and 3, which shoulder is normally spaced from thebracket 29 as shown in Figure 1. A spring 33 connecting with thebracket-29 engages the inner end port-ion of the lever as indicatedat34c and acts to -yie'ldably oppose movementof the lever under the actionof centrifugal force and serves torestore the lever to normal. A secondspring 35 extends between the outer end of the'we-ighted arm 27 and theinner end portion of" the weighted lever 31 which spring yieldablyopposes outward movement of the weighted arm under the action ofcentrifugal force and also acts to restore the arm to itsv normalinnermost po sition. Theouterend'of the arm 27 is formed with aninclined face 36 and the inner end portion of the weighted lever 81 isformed with a projection '37 which normally bears against the inclinedface 36 ad jacent the upper portion thereof in such fashion that-themovement of the weighted lever under the action of centrifu'ga lforcewill cause the projection "37 to move downwardly on the inclined plane36 and thereby exert a pressure on the outer end of the arm I 27tendingto rock the latter outwardly.

It will now be seen that on rotation of the rotary element in thedirection of-the arrow A i-n Figure 1, the weighted arm 27 and weightedlever 31 will be caused to rock outwardly in opposite directions underthe 7 action of centrifu alforce and that h son of the leverage effectedby the weighted lever on the arm 27, together with the actionofcentrifugal force on the arm 27, the initial outward movement of thearm 27 will be accelerated until the weighted lever is thrown out ofoperative relation to the weighted arm by moving against the stopafforded by the bracket 29, as shown in Figure 2. The weighted arm isdesigned to have a continued outward movement under action ofcentrifugal force after the action of the weighted lever thereon hasterminated; the weighted arm then moving outwardly under the action ofcentrifugal force in opposition to the spring which movement is limitedby a stop .38 formedon the bracket 36.v

By this construction the arm 27 and lever 31 constituting the weightedelements ofthe centrifugal governor will each swing outwardly under theaction of centrifugal force at low speed with their outward movementprogressing indirect ratio to the increase inspeed of rotation and theconsequent increase in centrifugal force, until thespeed of rotation andthe resultant centrifugal force is such as to cause the lever 31 to cometo rest, whereupon the action of thelever 31 in assisting outwardmovement of the arm 27 through themedium of the projection 37 on thelever riding over the inclined face 36 on the arm, will be terminated.The force exerted by the ac tion of centrifugal force on the lever 31being thus arrested when the speed of rota- I tion reaches apredetermined point there will be a diminution of centrifugal forceacting on the arm 27 when the speed ofrotation reaches a predeterminedpoint and there will he an increased resistance to the movement of thearm 27 under the action of centrifugalforce on further increase in speedabove the predetermined point by reason of the action of the spring 35on the arm 27. It accordingly follows that thearm 27 will initially moveoutwardly in direct proportion to increase in speed of rotation up to apredetermined point at a constant ratio and thereafter will move at alesser ratio at increasing speeds above the predetermined rate of speed.

-Mounted on the outer portion of the weighted arm 27 is a contact member39, here shown in the form'of a-wiper contact member, arranged totraverse a'series of con-v tact plates 40. carriedon the inner face ofthe end wall of a shell or housing 41 extending over and encircling therotary element.

It willbe noted by referring to Figures 1, 2 and 3 that the wipercontact member 39 will be caused, on swinging movement of the arm 27,to'mov'e outwardly and inwardly relative to the axis of rotation of therotary element so that it will traverse various circular paths of travelwithin the range of movement of the outer portion of the weighted arm.

By reason of the wipercontact'member being carried on a pivoted arm itwill also be caused to move on an arc and to be ad vanced or retractedalong the lines of its circular paths of travel and relative to a planeextending through the axis of rotation of the rotary element. V

The'wiper is thus caused to advance relative to its forward movement asthe speed ofthe rotary element increases, and is caused to retractrelative to its forward movement as the speed of the rotary elementdecreases.

It follows that as the wiper is advanced and retracted under the actionof varying speeds, the movement of its meeting with the contact platesand the consequent closing of the circuit will vary, thus advancing orretarding the moment of sparkingat the spark plug and accordingly varyinthe moment of ignition of the explosivec arge in the engine cylinderrelative to the position of the engine piston, as will be more fullyexplained hereinafter.

It will be understood that fluctuations in engine speed in the rangefrom low to high and arrangement shown, but may employ such changes andmodifications as come within the scope of the appended claims, it beingobvious that, in adapting the device to meet varying conditions withinthe range of advance and retardation of the sparking moment desired, thedegrees of movement of the wiper will be varied to meet the requirements.

I claim 1. In a device of the character described,

a rotary element, a weighted arm, a weighted lever, said arm and leverbein pivoted on said element and operable to ac vance collectively underthe action of centrifugal force up to a predetermined speed of rotationof said element, a yieldable connection between said arm and lever, aninclined plane on said arm, a projection on said lever operable on saidinclined plane to advance said arm relatively to said lever inoppositionto said yieldable connection, and means whereby said arm willbe caused to advance independent of said lever.

2. In a device of the character described, arm and lever, means forlimiting outward a rotary element, an arm pivoted on said movement ofthe arm, and means for limiting element, a lever pivoted on saidelement, said outward movement of said leverg'said last 10 arm and leverbeing arranged to swing outnamed means being arranged to arrest out- 5wardly in opposite directions under the acward movement of the leverbefore outward tion of centrifugal force, means for yield movement ofsaid arm is arrested. ably opposing outward movement of said 7 EDWARD G.NEWTON.

